Swelling wood, driving me nuts.

I just finished building an outdoor shower using 1x6 Meranti and Cedar posts. Link here:
http://jtpryan.smugmug.com/photos/597504579_acMNx-X3.jpg
Anyway, I had a rather tight tolerence on the door but I figured lets see if it is OK. Sure enough, after a monsoon the door swelled shut. While it was still in it's swelled state I removed the end piece where it shuts and cut it back 1/2". This left me a good 3/8" of clearance and while my mitres didn't look as good, all was well.
A week goes by and we get another monsoon. Bingo, the door has swelled beyond the clearance again, this time just in the middle. I had left a hacksaw blade width between each of the boards when I built it, which I was told was about right for movement in this kind of wood.
Anybody have any clever ideas on how to fix this? The dimensions on that door are roughly 5' x 27"
Jim
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I have the same problem with swelling wood driving me nuts but that's a different story all together.
Maybe you can have the door close against an overlapping stop. Then yoiu just cut it down to always be at least a little clear and the ever changing gap hides behind the overlap. With the right type of latch you should have enough play to have it work in any state of expansion.

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Another possibility (but would take a rebuild I assume) is to let the slats float in the frame with enough slot depth to accept the expansion. The frame is long grain in the width direction and shouldn't really change. I suppose your gate must be swelling at the center and it will probably tear the miters apart given time anyway, unless the slats can float. Pretty basic frame and panel now that I think of it.

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I would think that for doors like this, you want the horizontal pieces to determine the width of the door, with the wide vertical panels more "floating". Use wide rabbets on the edge of each panel-board so the boards overlap, and if they expand or contract it doesn't cause gaps. One fastener per board, near the edge that's on "top" rabbet-wise, so it holds two boards down without restricting expansion.
You'll need a diagonal cross-brace to keep the door from sagging, of course.
Option B is to rabbet the column an inch or so across, so the door overlaps the post more but won't stick if it expands a lot.
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I guess I should have been more specific about the construction. The edges are 1 3/4" square with a dado cut that the slats float in. So essentially they form a frame around the slats. I did leave some space, but evidently not enough. The dado I cut is 1/2" deep.
-Jim
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Oh, the 1x6's are tongue and groove.
-Jim
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jtpr wrote: ...

... Who told you that??? :)
I couldn't find published actual data; there are a number of classes/types that are commercially labelled as "meranti". From the picture I'd gather yours is one of the red (as opposed to yellow/white) species; what I did find indicates expansion is roughly on the order of oak (which also being ring-porous makes a certain amount of sense I'd guess).
Anyway, rule of thumb for oak would be about 1.5% or so for initially kiln-dried stock; for a nominal 6" plank that would translate into roughly 1/8" or 1/2" roughly for the 27".
From your description that seems too low, too.
Did you treat the ends before assembly to at least minimize wter absorption?
Other than either adding more spacing when dry or making the tolerances on the closing side larger there's not much to do to stop its movement.
You could minimize it somewhat w/ finishing but even that won't stop it; just slow it down some. --
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Thank you. The wood supplier I purchased it gave me that "rule of thumb". Anyway, Meranti is a Philippine Mahagony, so Mahogony would be a good wood to comapare it to. Yes, I treated it completely. Where did you find your figures? I would like to look up Mahogany.
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jtpryan wrote: ...

That is a merchantability name; has nothing to do w/ the actual western hemisphere mahoganies. "True" mahoganies such as Honduras mahogany belong to the family Meliaceae of the Swietenia genus whereas the trees that supply the timber for Philippine mahogany lumber and plywood belong to the huge plant family called Dipterocarpaceae. And in that family, the Shorea species has five distinct, commercially important trees named meranti..
Philippine "mahogany" is thus lumber from any of the above groups.
As such, its mechanical properties are _not_ closely related to New World mahoganies but more nearly approximate some of the oaks.
I did not find any actual published data on meranti species themselves other than shrinkage from wet to dry which isn't of much interest for already kiln-dried lumber.
A google search on "meranti" will lead to many sites outlining the above.
I don't have a hardcopy of the US FPL wood handbook and it's too large to make a quick search w/ dialup practical but it's link is below. Title: - Wood handbook - All Chapters: <http://www.fpl.fs.fed.us/products/publications/specific_pub.php?posting_id 335>
What I did look at was the following which did, as I say have the drying shrinkage data but that's not what is of interest for the subject question.
Title: Chapter 03 - Physical properties and moisture...: <http://www.fpl.fs.fed.us/products/publications/specific_pub.php?posting_id 789> <http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch03.pdf
You're welcome to look further, of course, but it doesn't look promising it'll be easy unless there is something in the Wood Handbook...
--


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jtpryan wrote:

Meranti - Phillipine mahogany (Shorea sp., luan, etc) - is totally different from either new world (Sweitana sp.) or African (Khaya sp.) mahogany. So no, mahogany would *not* be a good comparison wood.
--

dadiOH
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jtpr wrote:

Just take the door off. Tell the neighbor "Don't look, Ethel".
--
Gerald Ross
Cochran, GA
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Right, like there is a woman out there that COULDN'T look at me...
=Jim
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I have two.
1. turn the grain by 90 degrees. Allow more height in a capture channel that allows movement.
2. Have sliding panels - like you have now - but each are 2/3" width and fit in front and back - in capture channels. As the wood expands or shrinks, each part moves and has plenty of room. Almost like two doors in one.
Martin
jtpr wrote:

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